MagnaFlow Exhaust Products Performance Muffler 11386 — 4" x 9" Oval, 14" Length, Stainless Steel Satin Finish, High-Flow

MagnaFlow Performance Muffler 11386 is a universal, high-flow 4" x 9" oval muffler engineered to deliver a deep, resonant exhaust tone while improving exhaust flow and durability.

This stainless-steel muffler from MagnaFlow Exhaust Products combines a straight-through perforated core, two-stage acoustic packing, and a satin finish to balance reduced backpressure and refined sound. Designed as a universal unit, the 11386 measures 14" long with a 9" by 4" body and dual 2.5" ID inlet and outlet connections. It’s dyno-tested and built in the USA, backed by MagnaFlow’s limited lifetime construction warranty for long-term reliability.

What sound and performance changes should I expect?

The 11386 is tuned to produce MagnaFlow’s signature deep, full-bodied tone without excessive drone. Its straight-through design and perforated core improve exhaust evacuation, which can translate into more responsive throttle feel and optimized flow dynamics on many engines. Sound character will vary by vehicle, exhaust routing, and engine displacement.

• Deep, resonant bass-focused tone characteristic of MagnaFlow mufflers
• Reduced backpressure from straight-through perforated core
• Two-stage packing to control harsh frequencies and limit drone
• Dyno-tested architecture for balanced sound and flow

Will this muffler fit my vehicle and how do I install it?

The 11386 is a universal-fit muffler; measure your existing muffler and inlet/outlet tubing before purchasing. The body is 14" long with a 9" x 4" oval cross section and 2.5" ID connections on both ends. Professional installation or a qualified exhaust shop is recommended to ensure proper alignment, welding or clamping, and hanger placement.

• Body dimensions: 9" wide x 4" tall x 14" long — verify clearance
• Connections: dual 2.5" ID inlet and outlet — check pipe compatibility
• Installation: welding or heavy-duty clamps recommended; use proper hangers
• Fitment tip: mock-up before cutting; consider adapters for different pipe sizes

What materials and warranty protections does this muffler offer?

This muffler is constructed from stainless steel with a satin finish for corrosion resistance and a refined appearance. Internal components include a perforated core and multi-stage acoustic packing engineered to preserve flow while controlling tone. MagnaFlow covers the 11386 with a limited lifetime construction warranty, providing protection against manufacturing defects in construction.

• Exterior: satin-finished stainless steel for durability and rust resistance
• Internal: straight-through perforated core with two-stage acoustic packing
• Manufacturing: made in the USA with dyno-proven design
• Warranty: limited lifetime construction warranty from MagnaFlow

Who is this for: The MagnaFlow 11386 is aimed at drivers who want a robust, performance-oriented muffler that prioritizes free-flowing exhaust and a deep, refined tone. It’s ideal for custom exhaust builds, replacement of worn or restrictive mufflers, or enthusiasts seeking a durable stainless-steel option with a proven sound signature. Measure your vehicle’s space and pipe size beforehand and plan for professional installation if you want a neat, long-lasting fit.